In 2007–08, a genotype J mumps outbreak occurred among Aboriginal people in northern Western Australia, despite high vaccine coverage. In March, 2015, a second protracted mumps outbreak occurred in northern Western Australia and spread widely across rural areas of the state. This time the outbreak was caused by a genotype G virus and again primarily affected Aboriginal people. We aimed to describe the epidemiology of this outbreak.

Methods

In this population-based surveillance study, we analysed statutory notifications and public health case follow-up data from the Western Australia Notifiable Infectious Diseases Database and vaccination information from the Australian Childhood Immunisation Register. An outbreak case of mumps was notified if the affected person was living in or visiting a community in Western Australia where there was active mumps transmission, and if mumps infection was confirmed by laboratory diagnosis or by an epidemiological link. We analysed case demographics, vaccination status, and age-standardised attack rates in Aboriginal and non-Aboriginal people by region of notification. Laboratory diagnoses were made by real-time RT-PCR, serology, or both, and carried out by the sole public pathology provider in Western Australia.

Findings

Between March 1, 2015, and December 31, 2016, 893 outbreak cases were notified. 798 (89%) of 893 outbreak cases were reported in Aboriginal people. 40 (4%) of 893 people were admitted to hospital, and 33 (7%) of 462 men reported orchitis. Mumps attack rates increased sharply with age, peaking in the 15–19 age group. 371 (89%) of 419 people aged 1–19 years were fully vaccinated and 29 (7%) were partly vaccinated. Of the 240 people who tested positive by real-time RT-PCR and had also been tested for mumps-specific IgG and IgM, 165 (69%) were positive for IgG but negative for IgM, indicating the importance of RT-PCR testing for diagnosis in vaccinated populations. None of the cases from the 2007–08 genotype J outbreak were re-notified.

Interpretation

The number of mumps outbreaks reported in recent years among highly vaccinated populations, including Indigenous populations, has been growing. More widespread and pre-emptive use of the third dose of measles, mumps, and rubella vaccine might be required to control and prevent future outbreaks in high-risk populations. Research should explore the benefit of increasing the intervals between vaccine doses to strengthen the durability of vaccine protection.

July 27, 2018

Recently, mumps outbreaks among vaccinated persons in university settings have increased.

What is added by this report?

In 2016, large mumps outbreaks occurred at four Indiana universities. At some universities documentation of receipt of 2 doses of measles, mumps, and rubella vaccine (MMR) was not available and required substantial personnel time to verify. Implementation of policies for excluding susceptible persons from classes and other group settings was also difficult.

What are the implications for public health practice?

Outbreak-specific laboratory testing guidance to partners, standardized vaccination documentation, and evaluation of exclusion policies could aid outbreak management. The Advisory Committee on Immunization Practices currently recommends a third dose of MMR for persons at increased risk during a mumps outbreak.

The chief medical health officer confirms that to date there are over 230 mumps cases in the Puerto Montt region of Los Lagos. In Llanquihue province, 310 cases have been confirmed, 239 of them recorded in the regional capital.

April 18, 2018

Immunization rates in the Federation of Bosnia and Herzegovina are as low as 40% in some areas and continuing to decline, increasing the risk of large disease outbreaks. But, no one knows precisely why.

Growing vaccine hesitancy, misinformation in social media, lack of trust in the health system, a shortage of health workers and supply issues are all suspected reasons for low coverage rates. However, these are mostly assumptions with little evidence.

"Right now our immunization programming is based on a lot of assumptions," says Dr Sanjin Musa, epidemiologist at the Institute for Public Health in Bosnia and Herzegovina. "We need better data to understand which population groups have the lowest coverage and why it is so low."

Using WHO’s Tailoring Immunization Programme (TIP) – a structured research approach – the country is working to identify populations susceptible to vaccine-preventable diseases, diagnose barriers and motivators to vaccination, and recommend evidence-informed responses to improve coverage.

State of immunization

TIP was developed in 2013 by the WHO Regional Office for Europe to assist health care professionals, public health authorities and decision-makers in tailoring services to close gaps in immunization coverage. The first step in the TIP process is for countries to conduct a situational analysis to take stock of data on coverage and outbreaks, gather key stakeholders, and identify knowledge gaps.

In 2016, only 78% of children in Bosnia and Herzegovina received the third does of diphtheria-tetanus-pertussis (DTP)-containing vaccine, 79% received the third dose of polio, and 83% the first dose of measles vaccine – all falling short of global targets of at least 90 to 95%. Vaccination coverage also varies greatly within cantons and cities, and in some areas rates fall between 40-50%.

These low rates put the country’s population at-risk for large disease outbreaks. In the last decade there have been large outbreaks of measles, mumps and rubella, in part due to the disruption of immunization programmes during the war in the early 1990s, but also to vaccine hesitancy.

"With current large measles outbreaks across the Region, including in nearby Italy, Romania and Serbia, the country is constantly on high alert for outbreaks," says Dr Musa. Immunization is free and mandatory in the country, but there are no mechanisms to ensure compliance.

In Venezuela, since the first measles case was confirmed in EW 26 of 2017 until EW 12 of 2018, there were 1,006 confirmed cases (757 by laboratory and 249 by epidemiological link), including two deaths. The highest number of cases was observed in EW 38 and EW 40 of 2017 and between EW 8 and 11 of 2018, as shown in Figure 3.

About 67% of the confirmed cases were reported in Bolívar (the state with the highest cumulative incidence). Cases were also reported in Apure, Anzoategui, Delta Amacuro, the Capital District, Miranda, Monagas, and Vargas. The most affected age group among the confirmed cases is children under 5 years of age, followed by the 6-15 age group. The spread of the virus to other geographical areas is explained by, among other factors, the high migratory movement of the population due to formal and informal economic activity around mining and commercial activity.

As part of the intervention, a National Rapid Response Plan was designed to interrupt transmission of the virus, including the activation of national, regional, and municipal rapid response teams, implementation of vaccination strategies and activities, epidemiological surveillance, contact tracing, and training of health personnel; supported technically by the national level.

The country has provided more than six million doses of measles, mumps, and rubella (MMR) and measles / rubella (MR) vaccines to increase vaccination coverage in children and adolescents to interrupt viral transmission.

March 23, 2018

When a mumps outbreak hit Harvard University in 2016, epidemiologist Joseph Lewnard and immunologist Yonatan Grad, both at the Harvard T. H. Chan School of Public Health in Boston, wanted to know why. They saw two possibilities: Either today’s mumps strains have evolved to elude the immune response triggered by the vaccine, or protection from the vaccine simply wanes over time.

The pair compiled data from six previous studies of the vaccine’s effectiveness carried out in the United States and Europe between 1967 and 2008. (None of the studies is part of a current fraudulent claims lawsuit against U.S. vaccinemaker Merck.) Based on these data, they estimated that immunity to mumps lasts about 16 to 50 years, or about 27 years on average. That means as much as 25% of a vaccinated population can lose immunity within 8 years, and half can lose it within 19 years, researchers report today in Science Translational Medicine.

The team then built mathematical models using the same data to assess how declining immunity might affect the susceptibility of the U.S. population. When they ran the models, their findings lined up with reality. For instance, the model predicted that 10- to 19-year-olds who had received a single dose of the mumps vaccine at 12 months were more susceptible to infection; indeed, outbreaks in those age groups happened in the late 1980s and early 1990s. In 1989, the Centers for Disease Control and Prevention added a second dose of the vaccine at age 4 to 6 years. Outbreaks then shifted to the college age group.

Lewnard and Grad did not find evidence that the vaccine is any less effective today than it was a half a century ago. If that were the case, they would have expected to see outbreaks in younger people, which aren’t happening.

The researchers say future mumps outbreaks could be prevented by giving all 18-year-olds a third dose; they recommend clinical trials to test whether that approach works. Already, the U.S. Advisory Committee on Immunization Practices has recommended that people exposed to outbreaks get a booster shot.

“You can see that when we give these vaccines during outbreaks, the outbreaks stop,” says Laura Pomeroy, a disease ecologist at The Ohio State University in Columbus who was not involved in the study. The strategy has also worked well for the military, which has not seen mumps outbreaks since it began giving all new recruits an MMR dose in 1991.

Stanley Plotkin, a veteran vaccine expert with VaxConsult in West Chester, Pennsylvania, is not totally convinced that virus evolution doesn’t also play a role. Some studies suggest that the vaccine triggers a less potent reaction against today’s mumps viruses than those of 50 years ago, he says; that may play a role in the resurgence, in addition to waning immunity. “From my point of view, both factors are important,” Plotkin says.

January 29, 2018

More than 100,000 Rohingya refugees huddled in squalid, muddy camps in Bangladesh will be in grave danger from landslides when the mid-year monsoon season begins, a U.N. humanitarian report said.

There are now more than 900,000 Rohingyas in the Cox's Bazar area of Bangladesh, after 688,000 fled violence in Myanmar that flared up in late August. Aid workers say the camps sheltering the new arrivals are completely inadequate.

"Landslide and flood risk hazard mapping reveal that at least 100,000 people are in grave danger from these risks and require relocation to new areas or within the neighborhoods that they live in," the U.N. report said.

"The lack of space remains the main challenge for the sector as sites are highly congested leading to extremely hard living conditions with no space for service provisions and facilities. In addition, congestion brings increased protections risks and favors disease outbreak such as the diphtheria outbreak currently escalating in most of the sites."

Although a rapid vaccination programme appears to have staved off the risk of cholera, 4,865 have confirmed, probable or suspected diphtheria, and 35 have died.

The World Health Organization has vaccinated over 500,000 Rohingyas against diphtheria and on Saturday health workers began giving 350,000 children a second dose. The WHO also has 2,500 doses of anti-toxin, which is in short supply globally, to treat the deadly effects of the disease.

But a new health concern has arisen - mumps. The U.N. report said there had been an increase in cases in the past few weeks, and Rohingya refugees and host communities had never been vaccinated against the highly contagious disease, which is rarely fatal but can cause complications such as meningitis.

Most of the Rohingya refugees - almost 585,000 - are in an overcrowded area called Kutupalong-Balukhali.

"A high percentage of the land is unsuitable for human settlement as risks of flooding and landslides are high and are further aggravated by the congestion and extensive terracing of the hills," the U.N. report said.

"The anticipated flooding and landslides in the upcoming monsoon season will make a bad situation much worse."

A recent engineering assessment said all roads in the camp would be inaccessible for trucks, and the World Food Programme is considering using porters to distribute food, minutes of a Jan. 24 meeting of aid agencies involved in logistics said.

January 16, 2018

About 40,000 people in Västra Götaland who lack protection against measles are now offered a free vaccine.

"We do not want people to get sick in measles and we do not want any outbreaks, and then we need to increase immunity in the population," says Ann Söderström, Health Director in the Västra Götaland region.

After the recent measles case in Gothenburg, the regional board has now decided on free vaccine against measles, mumps and rubella for those who for some reason are not already immune.

The offer applies to people born 1960 and later, and adult asylum-seekers. The region estimates that it is about 40,000 people.

Those who know that they have had measles or know that they have been vaccinated with two doses of MPR vaccine should be immune. However, if you are unsure, Ann Söderström recommends that you contact your healthcare center and book the time for vaccination: "There is no danger of taking an extra dose if you have had measles or are vaccinated."

The offer of a dose of MPR vaccine applies effective today and throughout 2018. The regional board expects a cost of up to SEK 8.4 million [US$1,045,000].